1. Field of the Invention
The present invention relates to a guide rail device of a sun-roof for use in an automotive vehicle.
2. Description of the Related Art
A conventional guide rail device of a sun-roof related to the present invention is disclosed in U.S. Pat. No. 4,671,565. In the conventional guide rail device of a sun roof, a guide rail portion is formed into a U-shaped configuration and a pair of horizontally opposed guiding portions are continuously formed in the guide rail portion for uniform cross-section.
However, both of the guiding portions are formed so as to have an opening space in the lengthwise direction. This results in that the rigidity of the guiding portions are decreased. Particularly in forming the corner portion of the guide rail by bending an aluminium extruded member, the guiding portions located at the corners are easy to be transformed. Thereby, the guiding portions located at the corners are easy to contact with the sliding cables, so that the sliding resistance of the cables located at each of the corners increases. Thus, it is dangerous for the cables to fail to slide.